Conventional pipelines are formed by arranging separate lengths or sections of pipe end to end and then joining them together. Typically, central portions of each pipe section are coated with an anticorrosion coating during manufacturing and end portions of the pipe section are left uncoated to allow for joining. Pipe sections in a pipeline are often joined together using girth wells. Adjacent end portions of joined pipe sections should be coated with an anticorrosion coating after they are joined. Conventional liquid coating systems spray a coating around the exposed end portions of joined pipe sections in the field.
Coating systems can include a coating apparatus configured to be selectively mounted on a pipeline near an exposed joint surface. Typically, such a coating apparatus includes a frame that mounts a sprayer for spraying a curable liquid toward the joint surface. Frames can include movable frame members that open to install and remove the apparatus from the pipeline and close around the pipe. Operators must be careful when installing and removing the frame from the pipeline. Particularly when removing the frame from the pipeline after coating, it is important to avoid contacting the pipeline and damaging the coating. Certain coating apparatuses are configured to rotate around the pipeline to coat the entire circumference of the pipeline at a joint. In general, it is desirable for the frame to close securely around the pipe before spraying to ensure the coating apparatus stays mounted on the pipe as it rotates.
Typically, before or after spraying liquid coating material through a sprayer, flushing fluid is dispensed through the spray nozzle to purge contaminants and buildup. The flushing fluid can adversely affect the quality of the coating if it is allowed to contact the exposed end portions of the joined pipe sections or the recently sprayed on coating. Thus, conventional liquid coating systems orient the spray nozzle away from the pipe sections during flushing. After the sprayer has been flushed, the nozzle is repositioned to spray liquid coating material onto the exposed end portions of the joined pipe sections. Typical liquid coating materials produce overspray that should be removed from the target area during spraying.
Coating systems can include process rigs that deliver fluids that form the curable liquid to the coating apparatus. In conventional process rigs, day tanks store one or more components of the curable liquid. The components of the curable liquid are manually poured into the day tanks prior to spraying. As the day tanks are emptied, the operators must refill the day tanks to continue coating.
A fluid system connects a process rig to the coating apparatus. Typically, the fluid system will include various indicators of process conditions, such as temperature, pressure, level, and flow indicators. An operator monitors the indicators and adjusts various components of the system to control the process.
In general it is desirable for the operator to control the process to achieve desired process conditions during coating. It is thought that certain process temperatures, flow rates, pressures, etc. produce stronger and longer lasting polymeric coatings. An operator will typically attempt to achieve these process conditions each time a joint is coated. At later times, an operator of the pipeline may check the performance of the coatings formed by the coating system. Using conventional coating systems, the operator has no way to cross reference poorly performing coatings against the process conditions at which they were actually formed for purposes of improving future coating processes.